JPH03252474A - Resin composition for coating - Google Patents

Abstract

PURPOSE:To obtain the title composition useful as protecting film, etc., having excellent chemical resistance, transparency and smoothness, comprising a polymer having a specific fluorine-contained aliphatic ring structure and a solvent to dissolve the polymer as essential constituent components. CONSTITUTION:The objective composition comprising a polymer having a fluorine-contained aliphatic ring structure shown by the formula (l is 0-5; m is 0-4; n is 0-1; l+m+n is 1-6; R is F or CF3) having 0.05-0.35dl/g intrinsic viscosity measured in perfluoro-2-buthyltetrahydrofuran at 30 deg.C and a solvent (e.g. perfluorobenzene; preferably 0.1-20wt.% solution concentration) as essential constituent components.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a coating resin composition containing a polymer having a fluorine-containing aliphatic ring structure as an essential component.

[Prior art] A polymer having a fluorine-containing aliphatic ring structure is disclosed in Japanese Patent Application Laid-open No. 83
-238111, 238115 and U.S. Patent No. 47
As described in No. 54009, it is known that it is soluble in a specific solvent and can be coated, and that it has low crystallinity and thus provides a highly transparent coating film. Furthermore, coating films obtained from these polymers have the characteristics of fluororesins, such as low refractive index, low dielectric constant, low water absorption, and chemical resistance, so they are required to have these special physical properties. Suitable for various types of protective films.

However, the polymers described in these patents have problems such as the inability to obtain a thick film in one go because the solution concentration cannot be high, and the inability to obtain a smooth coating film due to the high viscosity of the solution. was there.

Furthermore, in applications such as protective films for semiconductors, there is a possibility that internal stress caused by thermal history during or after the formation of the coating film may adversely affect the surface of the semiconductor chip.

[Problems to be Solved by the Invention] The present invention solves the drawbacks observed in coating compositions whose main components are a polymer having a fluorine-containing aliphatic ring structure as described above and a solvent that dissolves the polymer. The object of the present invention is to provide a new coating resin composition containing a polymer having a fluorine-containing aliphatic ring structure as a main component, which has excellent film coating properties and provides a smooth coating film with little internal stress.

[Means for Solving the Problems] Based on the recognition of the above-mentioned problems, the present inventor has made extensive studies and found that a polymer having a fluorine-containing aliphatic ring structure having a specific molecular weight has high coating workability. It has been newly discovered that this material is extremely advantageous as a material that provides a smooth coating film with low internal stress.

Thus, the present invention was completed based on the above findings, and the intrinsic viscosity measured in perfluoro-2-butyltetrahydrofuran at 30°C is in the range of 0.05 di/g to 35 al/g. The object of the present invention is to provide a novel coating resin composition characterized in that it contains as essential components a polymer having a certain 7'-containing aliphatic ring structure and a solvent that dissolves the polymer.

In the present invention, the polymer having a fluorine-containing aliphatic ring structure may be exemplified over a wide range of examples, including those that are conventionally known or well-known. Therefore, in the present invention, a fluorine-containing polymer having the above-mentioned specific ring structure in the main chain is preferably employed.

For example, there are the following two methods for producing these polymers. However, it is not limited to these manufacturing methods.

Those resulting from 1° cyclization polymerization (1) CF20F2: ↓ Examples include those having a ring structure such as those obtained by radical polymerization. Among these, polymers having the following ring structures are typical.

However, the content of the present invention is not limited to these only.

(2) Ch=CF-CF2-CFCI-CF2-CF=
Ch↓ Radical polymerization (υSP 3202643 etc.) (3) CF2=CF-0-CF2-CF2CF2↓
Although radically polymerized polymers are shown as examples, in the present invention, the above-mentioned examples in which some of the fluorine atoms are replaced with other hydrogen atoms or organic groups, or 2° cyclic monomers obtained by metathesis polymerization are used. Items (USP 3978030) The above examples also include those having a ring structure such as those having a perfluoroaliphatic ring structure.

Therefore, the polymer having a specific ring structure in the present invention can be obtained more smoothly and advantageously by the above-mentioned cyclopolymerization, but in particular, the polymer has two polymerizable groups with different polymerizability in the molecule, and By using a monomer in which the linear part of the linking chain that connects these two polymerizable groups has 2 to 7 atoms, it is possible to reduce the side effects of gelation without using ultra-high pressure conditions or large dilution conditions. This allows the cyclization polymerization to proceed smoothly and advantageously while suppressing the occurrence of biochemical reactions.

As a monomer suitable for the above-mentioned cyclization polymerization, first of all, it is desirable that the monomer has two carbon-carbon multiple bonds having different polymerizability. Usually a carbon-carbon double bond is employed. For example, a fluorine-containing monomer with two non-symmetrical multiple bonds, a vinyl group and an allyl group, a vinyl ether group and a vinyl group, a fluorine-containing multiple bond and a hydrocarbon multiple bond, a perfluorinated multiple bond and a partially fluorinated multiple bond. Examples include: Secondly, it is desirable that the number of atoms in the straight portion of the connecting chain connecting these two carbon-carbon multiple bonds is 2 to 7. The number of atoms in the straight part of the connected chain is 0~
When the number is 1, cyclization polymerization is difficult to occur, and the same is true when the number is 8 or more. Generally preferred is a case where the number of atoms is 2 to 5.

Further, the connecting chain is not limited to a linear shape, and may have a side chain structure or a ring structure, and the constituent atoms are not limited to carbon atoms, but may be 0. It may also contain heteroatoms such as S and H. Thirdly, it is desirable that the fluorine content be 10% by weight or more. If the fluorine content is too low, the specificity of fluorine atoms will be exerted and the fluorine atoms will become separated. Naturally, perfluoromonomers are preferably employed.

Specific examples of the above-mentioned specific fluorine-containing monomer include CF2
=CFOChCF=Ch, CF2=CFOCF2CF
2CF=CF2CF2=CFOCF2CFCF=CF2
．． CF2=CFOCF20CF2CF=CF2CF3 CF2=CFOCF2CF"C)+2.CF2"CFO
CF2CF2C)! =CI(2゜CF220FOCF2
(CH2),NHCC[(204(21 (X is an integer of 0 to 3) CF2 etc. may be exemplified.

In the present invention, those having one vinyl ether group such as CF2=CF〇- are preferably employed in terms of polymerization reactivity, cyclopolymerizability, gelation suppression, etc. In particular, perfluoroallyl vinyl ether (CF2= CFOCF2CF
=CF2) and perfluorobutenyl vinyl ether (CF2=CFOCF2CF2CF=Ch).

The above-mentioned monomer components can be used alone or in combination of two or more, and there is no problem even if they are copolymerized in combination with other copolymer components to the extent that the essence of these components is not impaired. If necessary, the polymer may be crosslinked by some method.

Other monomers to be copolymerized are not particularly limited as long as they have radical polymerizability, and include fluorine-containing monomers,
A wide range of hydrocarbons and others may be exemplified. Of course, these other monomers may be used alone in radical copolymerization with the monomer capable of introducing the specific ring structure, or two or more of these other monomers may be used in combination to carry out the above copolymerization reaction. You can let them do it. In the present invention, it is usually desirable to select fluorine-containing monomers such as fluoroolefins and fluorovinylethers as other monomers. For example, preferred examples include tetrafluoroethylene, perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, or perfluorovinyl ether containing a functional group such as a carboxylic acid group or a sulfonic acid group. ,
Examples include chlorotrifluoroethylene.

As for the copolymer composition, in order to take advantage of the characteristics of the specific fluorine-containing aliphatic ring structure aimed at in the present invention, the composition of the cyclic structure is preferably 20% or more, and more preferably 4% or more.
It is desirable that it is 0% or more.

In the present invention, as a method for crosslinking the fluorine-containing polymer, commonly used methods can be used as appropriate. Crosslinking can be effected by adding or by using radiation or the like.

The molecular weight of the above polymer is perfluoro-2-butyl-
The intrinsic viscosity measured in 1-oxa-cyclopentene at 30°C is 0. 05dl/g to 0. It needs to be in the range of 35 dl/g. If it is less than 0.05, it becomes grease-like even after drying and cannot stand on its own as a single film. Moreover, if it is 0.35 or more, the properties such as high concentration and low viscosity, which are the characteristics of the present invention, will not be exhibited.

The molecular weight of the above-mentioned polymer can be appropriately adjusted within a preferred range by methods such as lowering the monomer temperature during polymerization, increasing the temperature of the initiator, and adding a chain transfer agent.

Furthermore, various additives such as antioxidants and ultraviolet stabilizers may be added to the fluorine-containing resin composition of the present invention in order to improve its practicality.

In the composition of the present invention, the solvent for dissolving the specific fluororesin is not limited as long as it dissolves the above-mentioned polymer, but perfluorobenzene, "'Afluid °'" (product name: Asahi Glass Co., Ltd. Suitable examples include Fluorinert (trade name: fluorinated liquid manufactured by 3M Company), trichlorotrifluoroethane, etc. Naturally, two or more appropriate types can be used in combination as a solvent. Especially in the case of a mixed solvent, hydrocarbons, alcohols, and other organic solvents can also be used together.The solution temperature is 0.
01wt%~50wt%, preferably 0.1wt%~
It is 20wt%.

In order to perform coating using the composition of the present invention, all conventional coating methods such as flash coating, poison tab blade coating, coating using a bar coater, spray coating, and spin cord can be employed. In particular, when smoothness is required, it is preferable to use a spin cord. When it is desired to form a relatively thick film on a small area, such as a protective film for a semiconductor chip, application by botting, in which a highly concentrated solution is directly dropped, is preferred.

[Examples] Next, examples of the present invention will be explained in more detail, but it goes without saying that this explanation does not limit the present invention.

Synthesis Example 1 35 g of perfluoroallyl vinyl ether, trichlorotrifluoroethane (hereinafter abbreviated as R113)
5g of water, 150g of ion exchange water, 20g of methanol
and 35 mg of (C3F7COO)2 as a polymerization initiator
was placed in a pressure-resistant glass autoclave with an internal volume of 200 m1.

After purging the system with nitrogen three times, suspension polymerization was carried out at 26@C for 23 hours. As a result, 28 g of Polymer A was obtained.

When we measured the infrared absorption spectrum of this polymer, we found that
18600m- due to the double bond present in the monomer
No absorption near 1,1840 cm-co was observed.

In addition, this polymer was dissolved in perfluorobenzene and +s
When the NMR spectrum of Bi' was measured, a spectrum showing the following repeating structure was obtained.

The intrinsic viscosity [η] of this polymer is “Fluorinert”
FC-75 (product name = perfluoro (2-
A liquid whose main component is FC-75 (hereinafter abbreviated as FC-75), which has a temperature of 0.30 at 30° C. The glass transition point of the polymer is 69°C, and it is a tough, transparent glass-like polymer at room temperature. Moreover, the 10% thermal decomposition temperature was 462'C.

Synthesis Example 2 35g of perfluorobutenyl vinyl ether, R1
5g of 13, 150g of ion exchange water, 2 of methanol
0 g and 90 mg of diisopropyl peroxydicarbonate as a polymerization initiator were placed in a pressure-resistant glass autoclave having an internal volume of 200 m1.

After purging the system with nitrogen three times, suspension polymerization was carried out at 40'C for 23 hours. As a result, 28 g of Polymer B was obtained.

When we measured the infrared absorption spectrum of this polymer, we found that
1660Cm- due to the double bond present in the monomer
+, there was no absorption near 1840 cm-+. Furthermore, when the NMR spectrum of +sF was measured, Synthesis Example 1
Similarly, a spectrum corresponding to a ring structure was obtained.

The intrinsic viscosity [η] of this polymer was 0.32 at 30°C in FC-75. The glass transition point of the polymer is 110
It is a tough and transparent glass-like polymer at room temperature.The 10% thermal decomposition temperature was 465°C.

The water absorption rate is 0.01% or less, and the dielectric constant at room temperature is 2.2 (8
0 Hz to IMHz), and the volume resistivity was 10'7 or more.

Synthesis Example 3 35g of perfluorobutenyl vinyl ether, R11
5g of 3, 150g of ion exchange water, 30g of methanol
g and 9On+g of diisopropyl peroxydicarbonate as a polymerization initiator were placed in a pressure-resistant glass autoclave having an internal volume of 200 m1.

After purging the system with nitrogen three times, suspension polymerization was carried out at 40° C. for 23 hours. As a result, 25 g of Polymer C was obtained.

When we measured the infrared absorption spectrum of this polymer, we found that
1680cm- due to the double bond that existed in 1,680cm-
+, there was no absorption near 1840 cm-r. Furthermore, when the NMR spectrum of 19F was measured, as in Synthesis Example 1, a spectrum corresponding to a ring structure was obtained.

The intrinsic viscosity of this polymer [η is 30″C in FC-75
It was 0.24. The glass transition point of the polymer is 11
0°C, and is a tough, transparent glass-like polymer at room temperature. Moreover, the 10% thermal decomposition temperature was 460°C.

Synthesis Example 4 35g of perfluorobutenyl vinyl ether, R11
3 g of 3, 100 g of ion-exchanged water, and 30 g of diisopropyl peroxydicarbonate as a polymerization initiator.
mg was placed in a pressure-resistant glass autoclave with an internal volume of 200 m1.

After purging the system with nitrogen three times, suspension polymerization was carried out at 40° C. for 23 hours. As a result, 26 g of polymer was obtained.

When we measured the infrared absorption spectrum of this polymer, we found that
1660cm- due to the double bond present in the monomer
+, there was no absorption near 1840 cm-+. Furthermore, when the NMR spectrum of 1'F was measured, Synthesis Example 1
Similarly, a spectrum corresponding to a ring structure was obtained.

The intrinsic viscosity [η] of this polymer is 30'C in FC-75.
It was 0.62. The glass transition point of the polymer is 11
0'C, and is a tough, transparent glass-like polymer at room temperature. Moreover, the 10% thermal decomposition temperature was 465°C.

Examples Polymers A to C obtained in Synthesis Examples 1 to 3 were dissolved in a fluorinated solvent (Flonana-FC-43'' manufactured by 3M Company) to obtain compositions 1 to 11 shown in Table 1. .

Next, using these, a spin code was performed on a glass plate at 50 Orpm. Thread mass during coating, 180℃
Table 1 shows the results of evaluation of foaming and dry film thickness during drying at 2° C./min (temperature raised at 2° C./min, held at 180° C. for 1 hour).

Comparative Example Using the high molecular weight polymer obtained in Synthesis Example 4, evaluation was carried out in the same manner as in the Examples. The results are shown in Table 2.

[Effects of the Invention] In the composition of the present invention, since the polymer having a fluorine-containing aliphatic ring structure has a small molecular weight, a solution with a higher viscosity can be obtained at the same temperature than when a high molecular weight polymer is used. A coating film with good spreadability and smoothness can be obtained. Furthermore, since a solution with a high solid content temperature can be used, it also has the effect that a thick film can be obtained with one coat.

Claims (1)

[Claims] 1. 3 in perfluoro-2-butyltetrahydrofuran
The intrinsic viscosity measured at 0°C is from 0.05 dl/g to 0.
1. A coating resin composition comprising, as essential components, a polymer having a fluorine-containing aliphatic ring structure in a range of 35 dl/g and a solvent that dissolves the polymer. 2. The coating resin composition according to claim 1, wherein the polymer having a fluorine-containing aliphatic ring structure is a polymer having a ring structure in the main chain. 3. The coating resin composition according to claim 1, wherein the polymer having a fluorine-containing aliphatic ring structure is a polymer having a ring structure in the main chain obtained by cyclization polymerization.